AIM: To induce lymphoid stem cells and/or T-cell precursors to diffe rentiate into functional mature T lymphocyte, and to increase the surface marker of T lymphocytes such as CD + 3, while embryonic stem(ES) cells differentiate d into hematopoietic stem/progenitor cells(HSPCs) in vitro . When they were i njec ted into lethally irradiated mice, these differentiated cells had the advantage in immune reconstitution. METHODS: Embryonic stem cells formed e mbryoid bodies(EBs) in the medium containing methycellulose, hematopoietic growt h factors(HGFs) was added to the culture system on the 6th day, thymopeptide was added at the same time. Flow cytometry were performed to detect the surface mar ker CD 34 and CD 3 of the differentiated cells. Finally the differentiated cells were injected into lethally irradiated mice, 60 days later, the incidence rate of graft versus host disease(GVHD) was taken as the mark of cell mediated immunity, PCR was performed to detect the sex determining region of the Y-chromo some(Sry) in bone marrow cells and spleen cells of the survival host female mice . RESULTS: The percentage of CD + 3 T lymphocytes was 10.52% a nd the incidence rate of GVHD was 0% on the 13th day, but they respectively rose up to 22.93% an d 100% if thymopeptide was added in the procedure of inducing ES cells to differ entiate into HSPC in vitro . CONCLUSION: The quantity of CD + 3 T lymphocytes increased in medium containing thymopeptide when ES cells differe ntiated into CD 34 + HSPC.

AIM: To investigate multi-potential of rat bo ne marrow mesenchymal stem cells (rBMMSC) and mutation inclination, the rBMMSC w ere long passaged in vitro. METHODS: Cellular cycles of diff erent passages were assayed by FA CSan flow cytometry and karyotypes of passage 6, passage 25 and passage 45 were compared by G-binding analysis. RESULTS: The early passages and long-term passages all showed st rong proliferation; passage 6, passage 25 and passage 45 all showed normal karyo type. CONCLUSION: Long-term culture and passage of rBMMSC still remain s strong proliferation. With this capability, the mutation inclination is not enhanced.

AIM: To investigate the differentiation from human mesenchymal stem cells (hMSC) to adipocytes.METHODS: hMSC were separated from rib marrow and expanded in culture medium. To detect the surface antigens, the labeled cells were analysed on a FACScan flow cytometer. hMSC were induced with dexamethasone, insulin, 1-methy1-3-isobutylxanthine and indomethacin which acted as adipocyte differentiation inducer. The cells were stained with Oil Red O. The number of adipocytes were counted on a phase-contrast microscope.RESULTS: hMSC were expanded as undifferentiated cells in culture for more than 5 passages. The isolated cultured MSC comprised a single phenotypic population and displayed a fibroblast-like morphology. These expanded, attached MSC were uniformly positive for CD29, CD44, CD90, CD105, CD166 and didn't express CD14, CD34, CD45, CD11a. After induced with induction medium, lipid vacuoles were first detectable within the cells at 48 hours. Two weeks later, more than 85% MSC differentiated into adipocytes which displayed a perinuclear accumlation of lipid vacuoles, as detected by Oil Red O. CONCLUSION: hMSC can be induced to differentiate into adipocytes. [

AIM: To investigate the differentiation from human mesenchymal stem cells (hMSC) into osteoblasts. METHODS: MSC were separated from human marrow with Ficoll-Paque reagent and expanded in cuture medium. To detect the surface antigens, The labeled cells were analysed on a FACScan flow cytometer. hMSC were induced to differentiate from mesenchymal stem cells into osteoblasts with dexamethasone, vitamin C, ?-GP. Cell morphology?AP activity?calcium deposition and osteopontin were detected. P10 MSC were compared to P3 MSC in the tendency of osteoblastic differentiation. RESULTS: The cultured MSC comprised a single phenotypic population and displayed a fibroblast-like morphology. hMSC showed a strong self-renewal capacity. After primary culture, approximately (5-6)?10 5 cells were obtained. These expanded attached MSC were uniformaly positive for CD29,CD44,CD59,CD105,CD166 and didn't express CD11a, CD14, CD33, CD34, CD45, CD38, CD80, CD86, CD117. After osteoblasts induction, the cells changed from spindle-shape to cuboidal and polygonal in cell morphology. The AP activity increased gradually and many scattered calcium nodes were observed. The expression of osteopontin was positive. CONCLUSION: hMSC can be induced to differentiate into osteoblasts.

AIM: To investigate the effects of PD98059 on the differentiation from mesenchymal stem cells to osteoblasts.METHODS: hMSC were separated from human marrow and expanded in cuture medium. hMSC were induced with dexamethasone, ?-glycerophosphate, vitamin C which acted as osteoblast differentiation inducer. PD98059 was added into the osteoblasts induction medium. The cells were assayed with cell morphology, alkaline phosphatase (AP) activity and calcium deposition. RESULTS: The isolated cultured MSC comprised a single phenotypic population and displayed a fibroblast-like morphology. After induced with osteoblasts induction medium, the cells showed changes in cell morphology from spindle-shape to cuboidal and polygonal. The AP activity increased gradually and reached the peak in 12 days, then decreased. Many scattered tangerice calcium nodes were observed. PD 98059 significantly inhibited AP activity and calcium deposition in a dose-dependent manner. A striking observation of the present study was that a few adipocytes appeared in cultures that were treated with PD 98059 and osteogenic differentiation medium. CONCLUSION: These results indicated that osteogenic diferentiation from the hMSCs was related to the activation of the ERK.inCwhichactedasost

AIM: To investigate the differentiation from human mesenchymal stem cells(hMSC) into neuron-like cells by the increase in intracellular cyclic AMP. METHODS: hMSC were separated from human marrow with Ficoll-Paque reagent and expanded in culture medium. hMSC were induced to differentiate into neurons with Forskolin and 3-isobutyl-1-methyl-xanthine (IBMX). Neuron-specific enolase(NSE), neurofilament(NF), glial fibrillary acaidic protein(GFAP) were detected by immunohistochemistry. RESULTS: hMSC were expanded as undifferentiated cells in culture for more than 10 passages. Forskolin/IBMX can induce hMSC to exhibit a neuronal phenotype, expressing NSE and NF-M in 5 hours. But the neuron-like cells didn't express the glial astrocyte marker GFAP. CONCLUSION: hMSC can be induced to differentiate into neurons by increase in the intracellular cAMP.

AIM: To detect CD23 mRNA expression in B-cell lymphoma. METHODS: 20 pathological diagnostic conformed B-cell lymphoma samples were selected. Surface CD23 protein expression was examined by SP-immunohistochemistry and CD23 mRNA was detected by in situ hybridization with digotoxin labeled CD23 DNA probe.RESULTS: The positive rates of both surface CD23 protein and CD23 mRNA expression in B-cell lymphoma samples were more than 90%. CONCLUSIONS: The high expression of CD23 was showed in B-cell lymphoma both in mRNA and in protein levels. The results of this study was useful for understanding the molecular mechanism of B-cell lymphoma and for clinical diagnosis and treatment of the disease.

AIM: To observe the relationship between the immune deviation of Th1 and Th2 cell clones and class Ⅱ major histocompatibility complex (MHC) antigen expression in different stages of acute rejection in transplanted hearts. METHODS: Heart transplantation were performed in rats.Isografts and non-transplanted animals were used as control group. Donor class II MHC antigen expression were detected with monoclonal antibodies and immunostaining technique and the amount of type Ⅰ and Ⅱ cytokines mRNA expression were detected by semiquantitative RT-PCR in cardiac allografts. RESULTS: Myocardial IL-2 mRNA and donor class Ⅱ MHC antigen expression were significantly in creased, accompanied with development of acute rejection( P

AIM: The expression of the mouse ? 2 microglobulin (? 2 m) in NIH3T3 cells transfected with the mouse ? 2m sense and antisense RNA was detected to clarify the effect of mouse ? 2m sense and antisense RNA on the expression of MHC classⅠgene. METHODS: The mouse sense and antisense RNA, pcDNA3-? 2mSN and pcDNA3-? 2mAN, were constructed and were transfected into NIH3T3 cells by lipofectamine. RT-PCR and Western blot were used to detect the expression of ? 2m in those cells. RESULTS: The expression of the mouse ? 2m in the cells transfected with pcDNA3-? 2mSN was increased, while it was decreased in those cells transfected with pcDNA3-? 2mAN. CONCLUSION: pcDNA3 -? 2mAN can downregulate the expression of the ? 2m in NIH3T3 cells.

AIM: To construct a recombinant adenovirus expression vector containing CTLA4Ig gene.METHODS: The CTLA4Ig gene derived from the plasmid PCDNA3.0/CTLA4Ig by using polymerase chain reaction (PCR) was inserted into the backward position of cytomegalovirus (CMV) immediate early promoter of the shuttle plasmid (pAdTrack-CMV). After being identified by endonuclease, PCR and sequencing, the recombinant shuttle plasmid pAdTrack-CTLA4Ig was co-transformed into E.coli. BJ5183 cells with the adeoviral backbone plasmid pAdEasyl-1 to obtain the homologous recombination. The adenovirus was generated in 293 cells. A series methods such as PCR and fluorescence microscope was employed to identify the generated recombinant adenovirus. RESULTS: Recombinant CTLA4Ig adenoviruses were constructed and the titer of virus was generally up to 1.65?10 12 phaque forming units per liter (PFU/L). CONCLUSION: Success in constructing recombinant pAdTrack-CTLA4Ig will be the base of the further research on its expression in the mammalian cells, and be potenially used in the prevention of transplant rejection and autoimmunity diseases.